Multi-layer tube

Abstract

A multi-layer tube containing: (1) a barrier layer made of laminated fluoro resin, and (2) at least one outer layer. The barrier layer has a thickness no greater than 20% of the average thickness of the multi-layer tube, and consists of a homo polymer of chlorotrifluoroethylene having a melting point no greater than 220° C., a melt flow rate (MFR) between 0.1 and 10 g/10min at a temperature of 230° C., and a tensile modulus between 750 and 1500 MPa. The outer layer consists of a styrene elastomer. Optionally, an oxygen barrier layer is included between the outer layer and the barrier layer. The barrier layer and the outer layer are integrally laminated with each other by forming the barrier layer and the outer layer in a co-extrusion manner with an adhesive resin being interposed between the barrier layer and the outer layer.

We claim: 
     
       1. A multi-layer tube comprising
 a barrier layer consisting of laminated fluoro resin, and at least one outer layer, 
 the barrier layer having a thickness no greater than 20% of the average thickness of the multi-layer tube 
 wherein the fluoro resin constituting the barrier layer consists of a homo polymer of chlorotrifluoroethylene having a surface tension higher than or equal to 30 dyne/cm, a melting point no greater than 220° C., a melt flow rate (MFR) between 0.1 and 10 g/10 min at a temperature of 230° C., and a tensile modulus between 750 and 1500 MPa, 
 the outer layer consisting of a styrene elastomer having a tensile modulus of between 7 and 40 MPa and a tensile yield strength between 0.5 and 5 MPa, 
 the barrier layer and the outer layer being integrally laminated with each other by forming the barrier layer and the outer layer in a co-extrusion manner with an adhesive resin being interposed between the barrier layer and the outer layer. 
 
     
     
       2. The multi-layer tube according to  claim 1 , wherein said multi-layer tube comprises at least
 the barrier layer (A) consisting of a homo polymer of chlorotrifluoroethylene, and 
 the outer layer (B) consisting of a styrene elastomer having a tensile modulus of between 7 and 40 MPa and a tensile yield strength of between 0.5 and 5 Mpa, and 
 an oxygen barrier layer (C) interposed between the barrier layer (A) and the outer layer (B), 
 the barrier layer (A), the outer layer (B) and the oxygen barrier layer (C) being integrally laminated by forming these layers in a co-extrusion manner with an adhesive resin layer being interposed between layer the barrier layer (A) and the oxygen barrier layer (C) and another adhesive resin layer being interposed between the outer layer (B) and the oxygen barrier layer (C). 
 
     
     
       3. The multi-layer tube according to  claim 2 , wherein said of both adhesive resin layers consist essentially of a mixture of acid modified polyethylene and styrene elastomer or a mixture of acid modified polyethylene, styrene elastomer and epoxidized olefin resin. 
     
     
       4. The multi-layer tube according to  claim 3 , wherein said styrene elastomer of said adhesive resin is an SEBS rubber. 
     
     
       5. A multi-layer tube comprising
 a barrier layer consisting of laminated fluoro resin, and 
 at least one outer layer, 
 the barrier layer having a thickness no greater than 20% of the average thickness of the multi-layer tube, 
 wherein the fluoro resin constituting the barrier layer consists of a homo polymer of chlorotrifluoroethylene having a surface tension higher than or equal to 30 dyne/cm, a melting point no greater than 220° C., a melt flow rate (MFR) between 0.01 and 10 g/10 min at a temperature of 230° C., and a flexural modulus between 1200 and 1800 MPa, 
 the outer layer consisting of a styrene elastomer having a tensile modulus of between 7 and 40 MPa and a tensile yield strength between 0.5 and 5 MPa, 
 the barrier layer and the outer layer being integrally laminated with each other by forming the barrier layer and the outer layer in a co-extrusion manner with an adhesive resin being interposed between the barrier layer and the outer layer. 
 
     
     
       6. The multi-layer tube according to  claim 5 , wherein said multi-layer tube comprises at least
 the barrier layer (A) consisting of a homo polymer of chlorotrifluoroethylene, and 
 the outer layer (B) consisting of a styrene elastomer having a tensile modulus of between 7 and 40 MPa and a tensile yield strength of between 0.5 and 5 Mpa, and 
 an oxygen barrier layer (C) interposed between the barrier layer (A) and the outer layer (B), 
 the barrier layer (A), the outer layer (B) and the oxygen barrier layer (C) being integrally laminated by forming these layers in a co-extrusion manner with an adhesive resin layer being interposed between the barrier layer (A) and the oxygen barrier layer (C) and another adhesive resin layer being interposed between the outer layer (B) and the oxygen barrier layer (C). 
 
     
     
       7. The multi-layer tube according to  claim 6 , wherein of both adhesive resin layers consist of a mixture of acid modified polyethylene and styrene elastomer or a mixture of acid modified polyethylene, styrene elastomer and epoxidized olefin resin. 
     
     
       8. The multi-layer tube according to  claim 7 , wherein said styrene elastomer of said adhesive resin is an SEBS rubber. 
     
     
       9. A multi-layer tube comprising
 a barrier layer consisting of laminated fluoro resin, and 
 at least one outer laver, 
 the barrier layer having a thickness no greater than 20% of the average thickness of the multi-layer tube, 
 wherein the fluoro resin constituting the barrier layer consists of a copolymer of chlorotrifluoroethylene having a surface tension higher than or equal to 30 dyne/cm, a melting point no greater than 220° C., a melt flow rate (MFR) between 0.01 and 10 g/10 min at a temperature of 230° C., and a flexural modulus between 1200 and 1800 MPa 
 the outer layer consisting of a styrene elastomer having a tensile modulus of between 7 and 40 MPa and a tensile yield strength between 0.5 and 5 MPa, 
 the barrier layer and the outer layer being integrally laminated with each other by forming the barrier layer and the outer layer in a co-extrusion manner with an adhesive resin being interposed between the barrier layer and the outer layer. 
 
     
     
       10. The multi-layer tube according to  claim 9 , wherein said multi-layer tube comprises at least
 the barrier layer (A) consisting of a copolymer of chlorotrifluoroethylene, 
 the outer layer (B) consisting of a styrene elastomer having a tensile modulus of between 7 and 40 MPa and a tensile yield strength of between 0.5 and 5 Mpa, and 
 an oxygen barrier layer (C) interposed between the barrier layer (A) and the outer layer (B), 
 the barrier layer (A), the outer layer (B) and the oxygen barrier layer (C) being integrally laminated by forming these layers in a co-extrusion manner with an adhesive resin layer being interposed between the barrier layer (A) and the oxygen barrier layer (C) and another adhesive resin layer being interposed between the outer layer (B) and the oxygen barrier layer (C). 
 
     
     
       11. The multi-laver tube according to  claim 10 , wherein of both adhesive resin layers consist of a mixture of acid modified polyethylene and styrene elastomer or a mixture of acid modified polyethylene, styrene elastomer and epoxidized olefin resin. 
     
     
       12. The multi-layer tube according to  claim 11 , wherein said styrene elastomer of said adhesive resin is an SEBS rubber